The case is significant because new federal rules that go into effect this summer will require 401(k) plan service providers—such as record keepers and investment managers—to report detailed fee information to plan sponsors.

'What we need to do is provide options so that, case by case—employer and employee—they have choices. … And I think that, actually, is an important part of the future,' Joshua Gotbaum told the National Press Club on April 3.

The U.S. Senate on March 14 approved allowing corporate defined benefit pension plans to base their contribution calculations on interest rates over a 25-year average rather than current interest rates, which have sent contribution payments soaring.

The aggregate funding level of 422 pension plans offered by Fortune 1000 companies fell to 78 percent in 2011, down from 84 percent in 2010 and 81 percent in 2009, according to Towers Watson & Co. analysis.